Refractive surgery uses lasers to reshape the cornea to correct refractive defects of the eye. According to some techniques, a flap of the eye is lifted to expose a portion of the cornea that is reshaped by ablation using an excimer laser. The flap is then replaced. According to other techniques, a femtosecond laser makes incisions in the cornea to create a lenticule. The lenticule is removed to reshape the cornea.